# a = 100
# b = 200
# mul = lambda a, b: a * b
# print(mul(100, 200))


# def num():
#     a = int(input("请输入一个整数"))
#     if a % 2 == 0:
#         print(f"{a}是偶数")
#     else:
#         print(f"{a}是奇数")
#
#
# num()


def add():
    result = 0
    for i in range(1, 101):
        if i % 2 != 0:
            result += i
    print(result)


add()










